Self-adhesive label adhesive is a type of adhesive material that firmly attaches labels to various surfaces through its physical or chemical properties. There are numerous types of adhesives, and different types are suitable for different uses. The choice of adhesive is an important part of the label design process.
Adhesives can mainly be classified as follows:
1. By chemical composition: #
- Natural adhesives: Derived from natural substances such as starch and protein. These adhesives have low production costs but inferior aging resistance and water resistance.
- Synthetic adhesives: Mainly synthesized from petrochemical products, such as polyamides, polyethers, polyurethanes, etc. These adhesives have good water resistance, aging resistance, and high bonding strength.
2. By physical state: #
- Solvent-based adhesives: Dissolve the high polymer in one or more solvents to form a viscous liquid. During use, the solvent slowly evaporates, causing the adhesive to solidify.
- Emulsion adhesives: Disperse the high polymer in water or organic solvents to form a milky liquid. During use, water or solvent slowly evaporates, and the adhesive solidifies.
- Hot melt adhesives: A solvent-free, water-free, meltable solid adhesive. It has good adhesion in the molten state and solidifies quickly after cooling.
3. By reactivity: #
- Non-reactive adhesives: These adhesives will not undergo chemical reactions during application, such as various hot melt adhesives, pressure sensitive adhesives, etc. Their characteristics are fast curing speed and general bonding strength.
- Reactive adhesives: These adhesives will undergo chemical reactions during application, and the molecular structure will change during the curing process, such as epoxy adhesive, silicone adhesive, polyurethane adhesive, etc. Their characteristics are high bonding strength, good durability, but require curing time.
4. By use environment: #
- Water-resistant adhesives: Mainly used for labels that need to be waterproof or used in humid environments, such as laundry labels, beer bottle labels, etc.
- High-temperature-resistant adhesives: Mainly used for labels that need to withstand high temperature environments, such as oven labels, electronic device labels, etc.
- Low-temperature-resistant adhesives: Mainly used for labels that need to be used in low temperature environments, such as frozen food labels, medical sample labels, etc.
Considerations for selection #
When choosing an adhesive, the following factors usually need to be considered:
- Label usage environment: For example, whether it needs to be water-resistant, high-temperature-resistant, low-temperature-resistant, oil-resistant, etc.
- Surface characteristics of the object to be affixed: For example, whether the surface is smooth, whether it contains grease, etc.
- Performance requirements of the adhesive: For example, bonding strength, initial tack, aging resistance, etc.
- Environmental requirements: For example, whether it meets environmental standards such as no VOCs emissions.
In actual applications, the most suitable type of adhesive will be selected according to the specific label requirements.